The report says the program over-relies on self-reporting from distributors and certified redemption centers and lacks adequate controls to monitor the accuracy and completeness of information submitted to them.

This could risk underpayments by distributors and overpayments to certified redemption centers, according to the state auditor.

Uncertified redemption centers may also be operating and collecting reimbursements of deposits paid, as well as handling fees, in violation of state law.

The report also says the program remains exposed to the risk of exempt beverage containers, for which deposits and container fees were not paid, entering the redemption stream.

The auditor says management must strengthen control to ensure the program is collecting deposits and container fees from distributors and the costs of administering the program are minimized.

Hillary Clinton's office said "nothing nefarious was at play" when the former secretary of state used her personal email address, rather than one provided by the State Department, during her four years as America's top diplomat.